Protective device.



R. P. JACKSON.

PROTECTIVE DEVICE.

APPLICATION FILED m4. 7. 1914.

1,177,334. Pa ten ted Mar. 28,1916.

WITNESSES: 7, INVENTOR 1,0. S I i 1 defective electrical apparatus seqnently, thBSn remaining .EARK, PENNSYLVANIA, ASSIGNDE T0 WESTINGHOUSE MING CGMPANY, A COBPOBATIGN Q PENNSYLVA'NEA.

PROTECTIVE DEVICE.

TaaZZ whom it may concern:

Be it known that 1, Ear P. E.KC1S()N, a citizen of the United States, and a resident of Edgewood in the county of Allegheny and Stan, o iennsylvania, have in vented a new useful Improvement in Protective Devic of which the following is a specification. My invention e i and particularly to otective do sics .VlTlSil Will automatically operate co rem a dis tributing circuit as in Insure continuity of service.

In alternating current sys 'zeins, it is usual to supply power to distributing mains from a plurality of transformers connected in multiple in order to provide better voltage regulation at the cusi;orners premises. 'i'his arrangeinen'afi is objectionable because when one of the l ans-formers burns one or bemrcuiled, arererse flow of ourighe short circuited transformer and thus iniposes addition ad upon the remaining transformers 0f ZiQQliGd in "multiple. Contransformers wer previously supplied "d transformers and, in load 'lzhe' short circuited causes a heavy demand must supply vthe by the short ciao addition, carry transformer which for power.

It is customary to supply fuses between the secondary Winding of a transform and the distributing mains, the capacity of the fuses being: equal to the maximum output of the brai'fsforiner, Therefore it is necessary ihat the reverse-current; flow through the secondary of a defective transformer must equal the rating of the fuse before the defective transformer is cisconnecied from the distributing circuit.

When a large number of transformers are connected in muliiplc, the extra 1 1 posed upon each is relatively small, reason of thedropin roleage in the seconr ary rnain s, the liar f fectiveiransiormer is called upon carry a subslxunizially larger pcr'l'o'u oi the load than hhe more remote in miners, thus causing an excess currem to'he delivered protective "mend, as a result, fuse is blown. Similarly, the n ransformer,will. disc-ounce m nearest irons He ilpcciicetion of Letters Patent 'tributing transformer 1,

dfa'lribue 'l e ampere turns Patented Tiler Application filed fianuary 7, 19144. 'eez'ial No 2318, 288.

circuit and, in the end, all the transformers will be disconnect-sch because of the excessive overloadsf One object of my invention is to provide a protective means which will automatically operate to disconnect; defective transformers from distributing mains.

Another object of my invention is to provide simple and inexpensive means for performing the above mentioned function which is easy insfiall and requires no periodical inspections or delicate adjustn the accompanying drawing, I have illustrated diagrainmaeically a distributing system ei'ubodying a form of my invention. Only one disiribueing transformer is shown, huh it will be understood that any number may lJ provided which will adequately supply the power demanded from the secondary mains.

A transformer 1 steps down the lightension voltage impressed upon primary mains 2 and a voltage suitable for the secondary or distrihutino' mains and Associated with :he distributing transformer 1 is an auxiliary transformer 8 provided with a primary Winding 7 secondary Winding 8. The primary Winding: 7 and the secondary Winding 8 are connected in scries'relation respectively, with a primary Winding 9 and a secondary winding 10 of the dis The windings 7 ehe auxiliary t'ans'l'ormer 6 have ratio of ampere turns as that of windings and iii) of the distributing trans-- former 1. The auxiliary transformer 6 may he considered as a current or series transformer in which the value of the current in the secondary Winding 8 is equal, at all times, to the current traversing the secondary winding 10 of themain transformer 1. A current-responsive means, such as a fuse 13, is connected between the points 11 and 12 of the circuit of. the secondary Winding 8 of the transformer {5. to disconnecn the secondary winding 10 from distributine mains when holding means 15 are released by reason-of the action of cnrreufi-responsive means 13. 'A tensicna'l elenienli actuates the switch 14 to and 8 of the A switch 14: is adapted disc nneee the main transformer from the between primary and secondary windings oi the ire" sformers l and 6 are equal, the prim windings '7 and 9 of the trunsi'ormers own :n in the same direction, as indiwml by arrows 1'4" and 18. How in the secondary rtiiulings t5 and 10, as a result (if the aforementioned current 'fiou in the respective primary windings. is indi- (rated by arrows 19 and E20. respectively. in asmuch as the current flow in the secondary winding 8 equals the current iiowiu the secondary winding 10, under normal opersting conditions, ihe resultant current flow through the fuse 18 is neutralized and. consequently, all. the current supplied toihe distributing mains el' and mus flow through the windings 8 and 10 in .lation.

To further explain the norms]. cin'izeui flow through the above-mentioned secondary windings, consider the current as flowing in. the following circuit nau'ualy through the secondary winding 10 in the direction indiouted by (he ilffl'd? 20, the switch E. the pri" nisry mains at and 5 lead .21, 'the second- I cry winding 8 in the d eciion indicated by the arrow 19, and e. lee-o 32 to the secondary Wlnding 10. previously QXPiQUK-"Cl, the

otential dro T: throush the fuse is between the points 11 and 12 is neutralized, thereby preventing any current flow therethruugh.

in the event of iiunsflformer l becoming shorucircuiied or burned out the current v ing or disconnecting the switch is.

supplied to she distributing mains i and from the other transformers (not shown) of the system, flows in. a reverse direction through the secondary coil 14}. 'ihi. reversed current flow destroys the neiri-mlizstion of pctensial across the ponds 1i and and causes a iarge quantity of current to flow through the fuse which is adapted to be ruptured at a predetermined CIIHlQnE flow. As the fuse 13 releases Lhe holding means 15, the switch 1% is aciiuutech thereby discon necting the secondary coil. from the distribdcing mains. This action iinposes'upon the renmiuing iransfmiucrs the loud previously carried by the 'cmusi 'ier i but ii; protects said tinnsforniers iron] the heavy demand of current which nod is required by the transformer i. provid were not d is disconnected from the disfirlbuting circuit.

If the transformer 1 becon'ies 1- and destroys the normal radio primary and secondary sinpeie turns the.

potential drcp between the points and 1&2 Wlll not be neutralized and, consequenvci I a resultant current flow may traverse the fuse 13. in this event, the iuselg may s so rated as to blow oucwhcn a smell amount of current flowsthrou'gh it, 'therchy reiessi i oils I have shown a fuse 13, it will be understood that any current-responsive device The direction of current may be inserted and arrunged to be sctuuied when ihe neutralization oi the curreni flow between the points 11 and 12 destroyed.

A u- 3t unocis 00 1M my 1m en 1011 .s not limited to the specific apparatus disclcsed but may be embodied in any'suiiiable means for normally neutralizing or reducing current iiow clirou h said current-res )onsive means being neutralized under normal conditions. I The combination with a main and an auxiliary transformer each hsving primary V which are connected in groups comprising corresponding Windings. of curreni-respensive means connected in circuii, is one of said groups of Windings in order to disconnect them from cir-- Quit when abnormal. conditions obtain, the eleccroinotive force norinsily impressed upon said current-responsive means being neutralized.

3. The combination 'Witi'lli, main and en auxiiiury trsnsiorn'iereach having primary and secondary windings which are con and secondary 'Wind'ines nccted in 'rou is conim'isim corres oudin windings, the rz'lfcio of transformation of transformers being equal, of current responsive vmeans connected to one of said groups of windings in order to disconnect them from ci. an; when a predetermined wine of current. flows in said current-responsive means the electromotive force impresses thereupon. being neutralized under normal conditions, said current-responsive means being subjected to potential difierence when the. yer/i0 of transformation oi either cf ssid transformers is disturbed...

4i. 21in aiiternuting-currens distribuiiug sy: in comprising primary mains, secondary mains. a main transformer, an suxii isry transformer, the primsry'windiug's and secondary windings respectively of said zz'nusioriners being connected in series role-- tiensuip, and current responsire means con being neutralized under nor ins cendiiiens- An eiternsiingcurrent distributing system comprising primary mains, secondary mains, a main transformer, an auxiliary transformer, the primary windings and secondary windings respectively of said transformers being connected in seriesrelationship, and current-responsive means connected in shunt to said secondary winding of the auxiliary transformer and in series with said secondary winding of the main transformer, the current flow through said current-responsive means being neutraiized under normal conditions.

6. An alternating current dis ributing system comprising primary mains, secondit'y mains, a main transformer interposed oierebetneen, an auxiliary transformer the secondary \\'ll'idl1lf; of which is connected in series relation with a winding of the main transformer, and (:1Hl'slif-YBSPOHSlVE means for disconnecting the main transformer in circuit when a predetermined current flows through aid current-responsive means, said transformer windings being eiectrically connected to the current-responsive means to neutralize normally the cur-- rent flow therethrough.

7. An alternating current distributing system comprising primary mains, second ary mains, a main transformer, an auxiliary transformer, current-responsive means to disconnect one transformer from circuit when traversed by a predetermined current rent-responsive means to normally neutralize current flow therethrough.

8. An alternating current distributing system comprising primary mains, secondary mains, a main transformer, an auxiliarytransfonner, and a current-responsive means for disconnecting the main transformer from the secondary mains, secondary windings of said transformers being interconnected to normally neutralize the current flow through the current-responsive means.

9. An alternating current distributing system comprising primary mains, secondary mains, a main transformer interposed therebetween, an auxiliary transformer, and currentr.sponsive means electrically connected in multiple with a secondary winding of the auxiliary transformer and in series with a secondary Winding of the main transformer in order to disconnect the said secondary winding of the main transformer from the circuit, said transformer windings being adapted to neutralize normally the current flow through the current-responsive means' In testimony. whereof, I have hereunto subscribed my name this 31st day of Dec.,

RAY P. JACKSON.

Witnesses GOLDIE E. MCGEE, B. B. HINES. 

